<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			*{
				padding: 0;
				margin: 0;
			}
			
			.boxs{
				width: 800px;
				margin: 100px auto;
			}
			
			.boxs>div{
				float: left;
				width: 400px;
				height: 800px;
			}
			.boxs .left{
				background-color: red;
			}
			
			.boxs .right{
				background-color: blue;
			}

            .boxs .left .up-l{
            	display: none;
            }	
            
            .boxs .left .down-l{
            	width: 400px;
            	height: 800px;
            	background-color: rosybrown;
            }		
            
            .boxs .right .up{
            	width: 400px;
            	height: 400px;
            	background-color: gold;
            }
            
             .boxs .right .down{
            	width: 400px;
            	height: 400px;
            	background-color: green;
            }
            
            
            @media only screen and  (max-width: 800px) {
                 
                 .boxs{
                 	width: 600px;
                 }
                 
                 .boxs .right{
                 	display: none;
                 }
                 
                 .boxs .left{
                 	width: 600px;
                 }
                 
                 .boxs .left .up-l{
                 	display: block;
                 	width: 600px;
                 	height: 200px;
                 	background-color: black;
                 }
                 
                 .boxs .left .down-l{
                 	width: 600px;
                 }
                 
                 
            	
            }
            
            
            
			
		</style>
	</head>

	<body>

		<div class="boxs">
			<div class="left">
				<div class="up-l">
				</div>
				<div class="down-l">
				</div>
			</div>
			<div class="right">
				<div class="up">
				</div>
				<div class="down">
				</div>
			</div>
		</div>
		
		<div class="div01">
			
		</div>
		
		<div class="div02">
			
		</div>
		
	</body>

</html>